The lesson we need to give our sons before it's too late.

Lilie James' parents have endured the unimaginable. First, they lost their 21-year-old daughter in a senseless act of violence. Now, they've sat and listened as the confronting final moments of her life were picked apart in a courtroom.

An inquest has revealed Lilie's murder was meticulously calculated. Paul Thijssen went as far as practicing which hand he would use to hold the hammer he later used to bludgeon her to death. He hit her over the head at least 25 times, beating her so badly, Lilie was left unrecognisable.

His reason? It's gut-wrenching.

Lilie James had her life taken from her too soon. Image: Supplied.

Experts told the court Thijssen likely acted out of revenge, after Lilie ended their brief, casual relationship. He had a fragile sense of self that couldn't withstand rejection.

It prompted a sobering warning from Lilie's mother, Peta.

Listen to Mamamia's twice-daily news podcast, The Quicky discuss the Lilie James murder inquest. Post continues below.

Speaking through tears, Peta told the court: "As parents, if we are not teaching our sons how to respect a woman's opinions and choices and accept rejection, we could be setting our daughters up for failure.

"In our case, a moment in time we will never recover from."

Lilie was vibrant and independent, with a smile that could light up a room. It's something her parents will never get to see again.

"Lilie, sweetpea, I am so sorry we couldn't protect you from what happened that night," Peta said. "The guilt that I feel will stay with us forever."

It's a burden they shouldn't have to bear. But they do.

Women are dying because men cannot handle rejection. It's a devastating reality that continues to repeat itself.

Forensic psychologist Katie Seidler told the inquest although Thijssen wielded coercive control in his relationships, there were no obvious warning signs or indicators of violence.

He had no history of aggression, and Dr. Seidler concluded there was probably nothing that could have been done to prevent the gender-based violence.

But surely that can't be the whole story?

We only have to log in to social media to see how rife violent rhetoric is in today's society.

Lilie had a smile that could light up a room. Image: Facebook.

Following Donald Trump's presidential election win, there was a 4,600 per cent increase in mentions of the terms "your body, my choice" and "get back in the kitchen" on X in just two days, according to the Institute for Strategic Dialogue.

Misogynsts and incels who previously kept their vitriol to the darker corners of the internet are now loud and proud, emboldened by the likes of Andrew Tate.

According to the Anti-Defamation League, incels are a group of "heterosexual men who blame women and society for their lack of romantic success". They're a subset of the online misogynist community known as the "manosphere".

Incel culture creates a festering resentment between the sexes. It lures in men and boys searching for a sense of brotherhood. But as these self-declared "nice guys" fall deeper down the rabbit hole, it can have devastating, real-life consequences.

Netflix's show Adolescence aptly represents this toxic culture. It's all anyone's talking about, and rightfully so.

It follows the chilling case of 13-year-old Jamie, who is arrested on suspicion of murdering his classmate, Katie, who rejected him. It depicts how misogynistic online rhetoric is shaping the way boys view women and girls.

Jamie is overwhelmed by vengeance after being rejected. Image: Netflix

In Episode 2, Detective Bascombe's son explains how Jamie's views were influenced by the "80/20 theory": the notion that "80 per cent of women are attracted to 20 per cent of men." This means the remaining 80 percent of supposedly undesirable men have to "trick" women to date them.

Jamie later admits this influenced how he approached girls at school. His belief in the 80/20 theory led him to target Katie, who he thought might be vulnerable after being shunned by classmates.

"I just thought that she might be weak," he admits. "I thought when she was that weak, she might like me."

For her to reject him at her lowest point, well that cut deep. So he killed her.

Jamie in Adolescence is a chilling reflection of the path so many boys follow. Image: Netflix.

And this rhetoric exists in the real world, too.

Writer and comedian Tim Minchin recently explained why it's so easy for boys to get sucked into the manosphere.

"You're not seeing a lot of positive messages about how great straight, white blokes are. There's not a lot of stuff for you that makes you feel pride, that makes you feel good," he told Ways to Change the World podcast.

"There's a lot of stuff about how terrible you are, and they're just going to run into the arms of someone who lets them have pride. Watch them drift towards Andrew Tate."

It begs the question: how can we change the narrative? How can we help our boys to do better? To be better?

Like Peta James said, we need to teach our boys to accept rejection and value women's opinions. But maybe we also need to focus on lifting them up in healthy, non-toxic ways.

Because the alternative? It's another family sitting in another courtroom, listening to the horrific details of how their daughter died simply because she said "no."

Feature image: Facebook/Netflix.